Generating Solar Power After Dark

Solar farms that would serve two Western utilities are planning to use technology that will generate electricity after the sun goes down, a move that could be a potential game-changer for the industry.

The two farms being planned by SolarReserve of Santa Monica, Calif., would store the sun’s energy in molten salt, releasing the heat at night when it could be used to drive a turbine and generate electricity. Two utilities, NV Energy in Nevada and Pacific Gas and Electric, Northern California’s biggest utility, would buy the power.
The sun’s intermittent nature has made large-scale solar farms most useful as so-called peaker plants that supply electricity when demand spikes, typically in the late afternoon on hot days. But the ability of SolarReserve to store the sun’s energy for use at night would be a step forward in technology.

“The energy storage characteristics were a key factor in our selection of the Tonopah solar energy project,” NV Energy’s chief executive, Michael Yackira, said in a statement. The utility will be able to draw electricity from the solar farm more or less on demand, which makes it easier to balance the load on the power grid.

New York Times